I have a 36 on a pt19 h9, This 36 just wanted to run away, tryed different props that people said to try. today put on a 11.5-4 know the engine is running much better. Running on 25% oil,10S,15C, 5%nitro. Running a little rich at take off it will go rich lean on a single loop. If you do three it will go 2 stroke and not come out. tryed to start out a little richer will not then go to lean. It will fly all the pattern. There is a lot of bubbles in the full lines, put on new standard 4oz tank had to add pressure to stop some of the bubbles and make it run. I dont know if this is from the fuse is week and just shakes to much. Maybe a head shim or new needle for first problem, new plane for the second?

thanks Steve

I have a 36 on a pt19 h9, This 36 just wanted to run away, tryed different props that people said to try. today put on a 11.5-4 know the engine is running much better. Running on 25% oil,10S,15C, 5%nitro. Running a little rich at take off it will go rich lean on a single loop. If you do three it will go 2 stroke and not come out. tryed to start out a little richer will not then go to lean. It will fly all the pattern. There is a lot of bubbles in the full lines, put on new standard 4oz tank had to add pressure to stop some of the bubbles and make it run. I dont know if this is from the fuse is week and just shakes to much. Maybe a head shim or new needle for first problem, new plane for the second?

thanks Steve

Hi Steve

You will need to make sure that you have the engine mounted very solid, then make sure the nose of the airplane is solid, if it is not and vibrates you will have much trouble getting good engine runs
Also you need to have the tank mount solid and it would not hurt to have a bit of foam between the tank and fuse

Randy

    I bought a Hanger 9 PT-19 with the EVO .36 included, just intending to use the airplane for a sport/demo model, and I liked the looks of it. I had also heard early good reports about the EVO .36. When I get the chance, I'll comment on the airplane over on the ARF forum, but as the engine and model came right out of the box and built to the instructions, it was darn near unflyable! Sticking with the engine, I could NOT get the engine to needle at all, it would just run away and was pretty scary. I was told by several, "it just needs more break in!" and I told them that you have to have control over the run to break it in! I checked everything for tightness, but no change. I'm not against the rear needle valve for a set up, I used them with success on my son's models when he was young and shy of the prop, so I know they can work. But this one would not work at all. I read where someone else tried drilling the largest venturi for a needle valve and tried that, and got a handle on it finally, but not what it should have been in my opinion. I had been playing with it over the last year or so, and got it back off the wall to take to Oshkosh, and had issues again. All through this endeavor, it seemed to me that it was sucking air somewhere. This time, I took the back plate off, and found next to nothing for a rear gasket. Some kind of clear material that looked to be only a few thousandths thick, so I added a .010" paper gasket. I also noticed that the venturi didn't have any gasket or o-ring, so I got some from Jim Lee when I saw him at the Paducah, KY contest. I thought the large venturi was about the right size, but was too short, and needed better seating surfaces for the NVA so I made one that was a little taller. For prop through all of this, I was using an APC 10-4. It pulled the model well when the engine was cooperating, but I was still getting inconsistent runs. My next thought was to try a different prop, even though I thought the APC 10-4 surely couldn't be over loading the engine. Today I got out and tried a Thunder Tiger 11-4.5, but it didn't like that at all. Next I pulled out an APC 10.5-4.5 competition prop (the one with the long, narrow, pointy blades), and things got dramatically better. The winds were picking up and even just going around in circles was difficult, so I hung it up early today, but I'm going to pick up where I left off with the APC 10.5-4.5. Once I'm sure I got the engine completely under control, I can get back to trimming the model a bit more.
  Steve Smith has one mounted in an old model he bought from another guy here, and he started out with the same symptoms I had, am engine that would run away scary like, and would not needle, even with the needle all the way out!. He brought his back out today, and we checked it for back plate gasket and venturi gasket, and added both cut from a business card, and he tightened all the loose pluging screws in the needle valve assmebly. This is a bad idea on Evolutions part, too many potential places for air leaks. He put the engine back in, and got much better results. He's got some tank re-plumbing to do, and after we get some more solid ground runs, I think he could fly the model with it with some confidence.
     I read Randy Smith's reply to a post in another thread about using an OS R/C needle assembly from an R/C carb, and this makes a lot of sense. It's a much better needle assembly than the o-ring type that OS is using now, and is the same needle assembly that OS put on the rear needle versions of the FP.35 and .40. Dig into your junk boxes for those discarded R/C carbs and pull the NVAs from them! I'm going to try this at first opportunity.
   Now, one question. I had to add a brass Harry Higgley prop hub to get the airplane to balance, and it weighs about two ounces. Does this extra weight on the crankshaft affect the engine run? Any kind of flywheel effect, good or bad? I would guess that it could, seeing as it's all the way out on the end of the crank, and even a few thousands off center wil create some bad vibration. I plan to add the needed weight some other way and go back to what came on the engine regardless.
   I would appreciate any and all comments.
  Thanks a lot!
  Type at you later,
   Dan McEntee

  The 36 is/was more of a general purpose engine than a pure stunt piece. The new 60 is a stunt motor with a unique (from the rc) liner, head, case and crank. The needle assembly is also more of what you would expect for a stunt design.......

  Hi Dave;
    As I said, I wasn't looking at the combination as a world beater stunt set up, just something reliable to take off the wall for fun and demonstrations. I was expecting it to run in a "wet 2-stroke" type of run with the high RPM/flat pitch prop set up, and for a ball bearing engine, I expected it to be pretty smooth and predictable and the couple of EVO.36s that I have had experience with, they have not performed as advertised. I have worked part time at a local hobby shop for the last 28 years or so, and guys come to me for opinions on products. I bought a SIG Primary Force and built it stone stock as per instructions so I can look a customer in the eye and give them honest feedback on a product I use and sell, and the P-Force has performed as advertised. I bought the H-9 PT-19/EVO.36 combo with the same intentions, and could not get things to work as advertised. I know the market that the engine and airplane were developed for, and most of the R/C guys and beginner/intermediate C/L flyers I know would not have stuck it out to find their way through the problems. My intent is not to put down anyone's product, but in fact try to help the manufacturer find and cure flaws and potential problems. The best thing for the C/L hobby and for a hobby shop owner would be for these things to be flying off the shelves! All through the whole process, the engine has demonstrated that it can make a lot of power but just has not been as user friendly as I would like or what a newcomer to the hobby needs. I think it's a great value considering what all it comes with and I would like to get another one, but want to be sure I don't have to go through this whole process again. My question for the Evolution people is why they do not put any o-ring or gasket on the venturi?
     I'll have to take a look at my model and decide if I want to move the engine forward or not. I for sure want to get the Higgley heavy hub off of there and go through more prop experiments again. I can't get mine to like the props that some of the others here say they are using. The type of nose construction on the fuse may be a source of some problems, and I think that the nose should have been longer in the first place, along with a bit longer tail moment maybe. It would have made balancing a bit easier. If I can make the changes by next weekend, I'll report back on how it behaves.
  Thanks a lot for the input.
   Type at you later,
  Dan McEntee

I experienced many of the same problems others have mentioned. For me, the cure was to replace the factory venturi(s) with one I machined from delrin (.272" I.D.) and drill the case for a Super Tigre needle valve assembly. Prop is a Thunder Tiger Cyclone 11 x 4 1/2. Fuel is 10/20 - 1/2 castor and 1/2 synthetic. With this setup, it runs like my Magnum .36 XL, basically in a 2 - 2 break. Plenty of power and consistent. I was never happy with the factory rear needle valve assembly.
Chris Brainard

I agree with and applaud your method and point as to the "off the shelf" experience. I believe it's very important to get that right especially when you're trying to get some people back into u/c. I have had the best luck with mine using the middle size vent with the remote valve on muffler pressure. I also use the heavier tube type muffler on the PT 19. I like the MA 11x5 for the prop. I fly it in a fast 424. My brother Dennis has been trying to get me to move the stab back on my PT also. I like the idea from a stability POV if nothing else.. Now where did I put that Zona saw??

     I had to use the tube muffler for balance. It took 4 ounces of weight to balance the model, two of that with the tube muffler and the other two with the Higgley hub. I don't know why they made the fuse so short. A longer nose and loner tail would have made a better looking model and made balance easier and there was plenty of room in the box for it!. I had to make a 3/4" extension for the elevator horn to slow the controls down enough to make it stable. I think there is some negative incidence in the stab I need to take out also, turns way too easy inside. First thing I want to do is get rid of the Higgley hub in case it's causing any problems, then try some more different props.
    I still may order me up another one to see if later examples still exhibit problems, now that I know how to cure it. I don't mind doing the work, because I can. It's those that can't that concern me, and it's just nice to use something right out of the box and have it work like it's supposed to every once in a while!
  Type at you later,
  Dan McEntee

One thing I forgot to mention is the tongue muffler. I found it to restrictive and doubled the number of holes. The engine appeared to be overheating and straining in overhead manuevers and then sluggish to richen up when it should have. Opening the exhaust solved that. Also, I don't run pressure...just uniflow. Our flying field is 6100 feet above sea level and we need all the power we can get. I'm using this engine on a 49 oz. airplane with .018" diameter x 65'-0" (eyelet to eyelet) stranded cable. With this setup it works well for me.
Chris Brainard

    Hi Chris;
     I forgot to mention that also. I never tried the tongue muffler because it was too light. My buddy had it on his airplane, and it tended to over pressurize the tank and flooded the engine. I noticed the single row of holes and suggested that he do as you did and double or even triple the number of holes. His engine started to behave a little more when we went to atmosphere with the uniflow vent.
  Another question for Evolution about this engine; Why all the cooling fins all over the cylinder? I don't think it does anything for the looks of the engine, makes it heavier, and I wonder if it's possible to cause the engine to run "too cool" ?
   As much as this kind of stuff is a pain, I do look at it as part of the hobby, and like the challenge and feeling of accomplishment after you get some success in solving the problems.
  Type at you later,
   Dan McEntee

Has anyone tryed the supertigre 51 venturi and needle valve on the36. looked it up on tower and it has 7mm inside bore, but with the needle valve going thru, this should be close to the 6mm with the needle only going half way. Was going to order one but tower is out of stock

If anybody wants to do that and give the engine away, contact me and I'll give you my mailing address and pay for the freight.
Chris Brainard

Hay that a good idea about the os and st and then I can spend money on all the reworks they talk about on here.

Both mine and my brothers run great out of the box, the problem was the plane the pt19, the nose of the plane is weak. I dont like the rear needle valve it is tite to the tank. a o ring on the venturi make priming a breeze. People around here were put too small of a prop on them. 11.5/4 or 11/5  or the three blade they send with it runs fine. On my La 25 I put the Fp needle valve on it and a metal back plate. Dont know why so many people are having problems with the evo. In the begining it was a fuel problem, plywood on the noise of the plane took care of that. Still did not stand up to the figure 9 I did and it broke my rear needle valve. Time for a new plane.   

  I have yet to see or hear of a single Evo .36 that has run well out of the box.

I've had zero problems with mine, runs fine.  Starts are great even, steady, runs.  The airplane doesn't fly well, but that's my fault!

On the mufflers. I've had luck with the tongue opening the holes to .125". On the tube type I pulled the baffle and it sounds real nice and it only costs 2db.. I like the tube better because it's quieter even with the baffle removed... I haven't had the over pressure issue maybe because I run the larger (medium) vent. Also on the tube I moved the pressure tap into the manifold. Goop was flowing from the pressure tap to the tank when it was still in the tube portion of the muffler.

   Hi Dave;
   The above got me curious and had me pulling the muffler off my engine, and there is no baffle in mine. Completely empty inside. Are you talking about a cone like the one in the OS 2030 mufflers that the LA series uses?  I haven't had the "goop" issue with the pressure tap, but agree with the move to the stack and will do this at first opportunity. I think it is a more even and proper source of pressure also. By that I mean it doesn't tend to over pressurize the tank, of restrict the pressure flow from oil build up.
  Type at you later,
  Dan  McEntee

 Thanks Dave. I really don't mean to sound all negative, just a little disappointed and stating my personal experiences with the Evo. Good luck with the new bigger engine, I still need something for my P-40.

 Thanks again Dave, I don't intend to offend.

Hi Don. I went at the balance a little differently. I moved the engine forward the distance between the mounting holes by just aligning the rear holes in the engine mounts with the the front holes in the bearers and drilling new front holes in the bearers. It "fixed" the balance issue pretty well. As to the remote valve issue. I didn't have a lot of trouble with it but I did wear one out. I replaced the valve unit with on from an OS 4 cycle (it screws right in as a direct replacement) and it works well. I like the idea of the os rc carb valve mounted in the vent or the large vent with the pass through. The large vent was originally intended for high rpm work. The 36 is/was more of a general purpose engine than a pure stunt piece. The new 60 is a stunt motor with a unique (from the rc) liner, head, case and crank. The needle assembly is also more of what you would expect for a stunt design.......

Dave

What would you do to the Evo 36 to make it more of a pure "stunt piece"?  Will the venturi NVA from the 60 work on the 36?

I think that it has been posted that Horizon will have a new venturi set up with the needle valve going through the cinch bolt position. This should take care of most of the user concerns with the remote nva. Having a needle valve low certainly makes it easier to use in a full bodied stunter as far as tank,nva alignment is concerned..Incidentally the NVA system as used on the Evo 60NXCL is really a nice unit.
If you feel that you have to have the needle valve set into the venturi then this is at least a cleaner set up to accomplish the task. Venturi is from Just engines and it was origionally for an Irvine 36. It's throat is small enough to tame the engine and it needles nicely too.
Dennis

It just dawned on me that the Evo has the same mounting pattern as the Fox 35. That means that my underpowered Fox 35 Oriental is going to get an upgrade in performance. I'll post a performance report when the weather breaks and I can get out and fly it.